本文關(guān)鍵詞：生物質(zhì)熱解制備雙金屬催化劑及煤熱解中硫的轉(zhuǎn)化機(jī)制研究　出處：《中國科學(xué)技術(shù)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 生物質(zhì) 煤 熱解 雙金屬催化劑 六價(jià)鉻還原 硫轉(zhuǎn)化 熱重-紅外-質(zhì)譜機(jī)制

【摘要】：生物質(zhì)是一種豐富的可再生資源,熱解是生物質(zhì)的一種利用手段。通過熱解生物質(zhì)制備功能化材料是處置廢棄生物質(zhì)回收資源的有效手段,引起了學(xué)術(shù)界較大的關(guān)注。此外,熱解還是一種潔凈的煤利用方法,也是煤各種利用途徑中的一個(gè)關(guān)鍵中間過程。煤熱解過程中污染物的轉(zhuǎn)化關(guān)系到熱解的實(shí)際應(yīng)用。因此,在本文中,我們通過生物質(zhì)熱解合成了一種雙金屬催化劑,并研究了其環(huán)境應(yīng)用;利用TG-FTIR-MS在線分析手段研究了煤熱解過程中硫的遷移和轉(zhuǎn)化。本文的主要內(nèi)容和結(jié)論如下:1.生物質(zhì)熱解制備生物炭基功能材料是一種雙贏策略,既可以以環(huán)境友好的方式實(shí)現(xiàn)生物質(zhì)的充分利用,又可以實(shí)現(xiàn)功能材料的簡易合成。我們通過一種綠色簡單的方法,即生物質(zhì)熱解和置換反應(yīng),制備了一種碳負(fù)載的銅釕雙金屬材料(Ru-Cu/C)。負(fù)載痕量Ru的Ru-Cu/C對(duì)催化水合肼還原六價(jià)鉻有良好的催化活性,遠(yuǎn)優(yōu)于單金屬催化劑Cu/C和Ru/C。Ru-Cu/C在3分鐘內(nèi)可實(shí)現(xiàn)六價(jià)鉻的完全還原,且在不需額外沉淀過程的情況下總鉻去除率達(dá)到94%。我們對(duì)材料進(jìn)行了多種表征,結(jié)果顯示了雙金屬催化劑的協(xié)同效應(yīng)與其物理化學(xué)結(jié)構(gòu)之間的關(guān)系,如XPS結(jié)果顯示Ru-Cu/C中的Cu和Ru之間存在強(qiáng)烈的相互作用。我們探索了該催化過程的可能機(jī)制,發(fā)現(xiàn)六價(jià)鉻還原起主要作用的是Ru-Cu/C催化水合肼分解產(chǎn)生的活性氫。2.煤熱解是煤各種利用過程的中間階段,如氣化,燃燒,液化,同時(shí)煤熱解也是一個(gè)有效的脫硫方法。由于煤中硫種類和煤熱解過程的復(fù)雜性,煤熱解過程中硫的演化行為尚不清楚。為了開發(fā)和評(píng)價(jià)脫硫方法,認(rèn)識(shí)和理解煤熱解過程中硫的轉(zhuǎn)化極為重要。我們利用在線的熱重-紅外-質(zhì)譜聯(lián)用技術(shù)(TG-FTIR-MS)研究了添加CaO和不添加CaO的煤熱解過程中硫的轉(zhuǎn)化行為。我們檢測(cè)到了 10種含硫物質(zhì),包括H2S、SO2、S03、硫醇類和噻吩類化合物。結(jié)合TG-FTIR-MS提供的氣相產(chǎn)物結(jié)果和XRD和XPS給出的固相中硫的信息,我們解釋了煤熱解中可能的硫轉(zhuǎn)化機(jī)制。
[Abstract]:Biomass is a rich renewable resource, pyrolysis is a means of utilization of biomass, the preparation of functional materials through pyrolysis of biomass is an effective means to dispose of waste biomass recovery resources. In addition, pyrolysis is a clean coal utilization method. It is also a key intermediate process in various ways of coal utilization. The transformation of pollutants in coal pyrolysis is related to the practical application of pyrolysis. Therefore, in this paper. A bimetallic catalyst was synthesized by pyrolysis of biomass and its environmental application was studied. The transport and transformation of sulfur in coal pyrolysis were studied by means of TG-FTIR-MS on-line analysis. The main contents and conclusions of this paper are as follows:. 1. It is a win-win strategy to prepare bio-carbon-based functional materials by biomass pyrolysis. We can realize the full utilization of biomass and the simple synthesis of functional materials in an environmentally friendly way. We use a simple green method, that is, biomass pyrolysis and displacement reaction. A carbon-supported copper-ruthenium bimetallic material, Ru-Cu / C, was prepared. The Ru-Cu/C supported on trace Ru has good catalytic activity for the reduction of hexavalent chromium with hydrazine hydrate. Compared with Cu/C and Ru/C.Ru-Cu/C, hexavalent chromium can be completely reduced in 3 minutes. The removal rate of total chromium reached 94% without additional precipitation process. The results show the relationship between the synergistic effect of bimetallic catalyst and its physical and chemical structure. For example, XPS results show that there is a strong interaction between Cu and Ru in Ru-Cu/C. We have explored the possible mechanism of the catalytic process. It is found that the main role of hexavalent chromium reduction is the catalytic decomposition of hydrazine hydrate catalyzed by Ru-Cu/C. 2. Coal pyrolysis is the intermediate stage of coal utilization process, such as gasification, combustion and liquefaction. At the same time, coal pyrolysis is also an effective desulfurization method. Because of the complexity of sulfur species in coal and coal pyrolysis process, the evolution behavior of sulfur in coal pyrolysis process is not clear. In order to develop and evaluate the desulfurization method. It is very important to know and understand the conversion of sulfur in coal pyrolysis. We use the on-line thermogravimetric infrared mass spectrometry (TG-FTIR-MS). The conversion behavior of sulfur in the pyrolysis of coal with or without CaO was studied. Ten sulfur compounds were detected. It includes H _ 2S _ 2SO _ 2H _ 2O _ 3, mercaptan and thiophene compounds, combined with the gas product results provided by TG-FTIR-MS and the information of sulfur in solid phase given by XRD and XPS. We explain the possible sulfur conversion mechanism in coal pyrolysis.
【學(xué)位授予單位】：中國科學(xué)技術(shù)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O643.36;TQ530.2;X70

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本文編號(hào)：1414605